If this is true, then the WAN "O" port on both the Living Room AirPort Extreme and Loft AirPort Extreme has failed, the ethernet cable is defective or the LAN <--> Ethernet port on the main AirPort is defective, or the Ethernet switch is defective.
Power off both the Living Room and Loft AirPorts
Restart the main Basement AirPort Extreme
Temporarily,, connect a short Ethernet cable from one of the LAN <--> ports on the main AirPort to the WAN "O" port on the Living Room AirPort Extreme. That is the port that is closest to the AC power socket on the AirPort
Power up the Living Room AirPort Extreme and let it run a minute
Hold in the reset button on the back of the AirPort Extreme for 10 seconds and release. The reset button is located just the right of the AC power socket
After a minute, the Living Room AirPort's indicator light will be slowly blinking amber
Open AirPort Utility on your Mac Applications > Utilities > AirPort Utility
Click on the Other Wi-Fi Devices button

Click on AirPort Extreme xxxxxx
The AirPort Utility screen will change to display a screen that will look similar to the example below, except that you will see your AirPorts appear and the name of wireless network appear

Type in a device name that you want to call the AirPort. You can use the same Living Room name if you want
Click Next
The next screen that appears will look similar to the example below

Check closely to make sure that the info reads that the Living Room AirPort is being set up to extend the name of your wireless network using Ethernet
If the info reads that the Living Room AirPort is being set up to wirelessly extend the name of your network, the WAN "O" port on the Living Room AirPort is defective, the Ethernet cable is defective or the Ethernet port on your Main AirPort is defective.
If the setup goes correctly, you will see a screen that looks similar to this:

Click Done and you are Done.
Set up your other Loft AirPort Extreme the same way using a short Ethernet cable from the main AirPort to the Loft AirPort.
When you have both AirPorts working correctly, move the AirPorts back to the location where you want them. If your Ethernet cabling, Ethernet switch, etc are working correctly, then so too will the AirPorts be working correctly.
If the AirPorts are not working correctly when you move them back to their normal locations,you have a problem with the Ethernet cabling or the Ethernet switch.
Please post back on your results.